Spoken vs. Non-spoken spell

[foodiedb]

No: HPFGUIDX 147466

Hi all,
I was thinking about another way that one can get around Snape doing 
a genuine or effective AK.  Let's say that while he spoke the AK 
correctly, "inside" of him he was doing a wordless spell.  Would the 
wordless spell "take over" the spoken spell?
Good night,
David

It is our choices Harry, that show what we truly are, far more than 
our abilities. 
- Albus Dumbledore